I don't know what else to tell you, except add those 2 and see if it help's ?
Otherwise maybe someone with more know how will post.
PS you could go to maintenance and do the purge etc. like you said, but I am not sure of the outcome.

Thanks for trying. Those 2 other repos are on my list above, but you have to scroll in the code text pane. I added a little more to my code segment to show that there was nothing in /etc/apt/sources.list.

Wow, that's twice I missed something you posted, I guess it's time for me to get a pair of glasses.
Hang in there, I know someone on the forum who can help, I will pm him, and have him take a look at your situation. So, my and your repo's are the same, and so is everything else you posted, it's gotta be something obscure. Don't give up.